[PATCH] mtd: rawnand: meson: fix the clock after discarding sd_emmc_c_clkc
Liang Yang
liang.yang at amlogic.com
Sun Jan 9 19:28:46 PST 2022
Hi,
On 2022/1/7 17:57, Neil Armstrong wrote:
> [ EXTERNAL EMAIL ]
>
> Hi,
>
> On 07/01/2022 05:04, Liang Yang wrote:
>> Hi Jerome,
>>
>> On 2022/1/6 16:16, Jerome Brunet wrote:
>>> [ EXTERNAL EMAIL ]
>>>
>>>
>>> On Thu 06 Jan 2022 at 11:25, Liang Yang <liang.yang at amlogic.com> wrote:
>>>
>>>> Because EMMC and NAND have the same control clock register, so we
>>>> implement a 'sd_emmc_c_clkc'. Previously DTS is defined as below:
>>>>
>>>> sd_emmc_c_clkc: mmc at 7000 {
>>>> compatible = "amlogic,meson-axg-mmc-clkc", "syscon";
>>>> reg = <0x0 0x7000 0x0 0x800>;
>>>> };
>>>>
>>>> nand-controller at 7800 {
>>>> ......
>>>>
>>>> clocks = <&clkc CLKID_SD_EMMC_C>,
>>>> <&sd_emmc_c_clkc CLKID_MMC_DIV>,
>>>> <&sd_emmc_c_clkc CLKID_MMC_PHASE_RX>,
>>>> <&sd_emmc_c_clkc CLKID_MMC_PHASE_TX>;
>>>> clock-names = "core", "device", "rx", "tx";
>>>> amlogic,mmc-syscon = <&sd_emmc_c_clkc>;
>>>>
>>>> ......
>>>> }
>>>>
>>>> but in fact, above implementation is rejected. so now registering
>>>> a nand_divider.
>>>
>>> Can you give a bit of context ? a link to the discussion rejecting this
>>>
>> Maybe I mistake the meaning of [jianxin.pan at amlogic.com], so i need him to clarify it.
>>> As far as remember, things were getting done for A1 and stopped before
>>> clock part was finished. I'm saying the change is wrong, just that a
>>> discussion is needed before a decision is made.
>>>
>> ok.
>> previous discussion in this link:
>> https://lore.kernel.org/all/86789d73-5a6c-7729-ecd1-dcd342b2fcde@amlogic.com/
>> it never go on since v6.
>
> Looking at the serie I don't see any major blockers, if you're willing to take ownership
> of this patchset and send a v6 with all issues/comments addressed, it would be easier than
> restarting the whole design discussion
>
> Neil
Hi Neil, thanks for your advice.
After talking with [jianxin.pan], form this link
<https://lkml.org/lkml/2019/1/8/441>, it already moves futher and on v9,
so we decide to continue to work hard on it.
>
>>
>>>>
>>>> Change-Id: Ibeb4c7ff886f5886aac4d6c664d7bbd1b1bcb997
>>>> Signed-off-by: Liang Yang <liang.yang at amlogic.com>
>>>> ---
>>>> drivers/mtd/nand/raw/meson_nand.c | 88 +++++++++++++++++--------------
>>>> 1 file changed, 49 insertions(+), 39 deletions(-)
>>>>
>>>> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
>>>> index ac3be92872d0..4472363059c2 100644
>>>> --- a/drivers/mtd/nand/raw/meson_nand.c
>>>> +++ b/drivers/mtd/nand/raw/meson_nand.c
>>>> @@ -2,7 +2,7 @@
>>>> /*
>>>> * Amlogic Meson Nand Flash Controller Driver
>>>> *
>>>> - * Copyright (c) 2018 Amlogic, inc.
>>>> + * Copyright (c) 2018-2021 Amlogic, inc.
>>>> * Author: Liang Yang <liang.yang at amlogic.com>
>>>> */
>>>> @@ -10,6 +10,7 @@
>>>> #include <linux/dma-mapping.h>
>>>> #include <linux/interrupt.h>
>>>> #include <linux/clk.h>
>>>> +#include <linux/clk-provider.h>
>>>> #include <linux/mtd/rawnand.h>
>>>> #include <linux/mtd/mtd.h>
>>>> #include <linux/mfd/syscon.h>
>>>> @@ -55,6 +56,7 @@
>>>> #define NFC_REG_VER 0x38
>>>> #define NFC_RB_IRQ_EN BIT(21)
>>>> +#define NFC_CMD_FIFO_RESET BIT(31)
>>>> #define CMDRWGEN(cmd_dir, ran, bch, short_mode, page_size, pages) \
>>>> ( \
>>>> @@ -104,6 +106,9 @@
>>>> #define PER_INFO_BYTE 8
>>>> +#define CLK_DIV_SHIFT 0
>>>> +#define CLK_DIV_WIDTH 6
>>>> +
>>>> struct meson_nfc_nand_chip {
>>>> struct list_head node;
>>>> struct nand_chip nand;
>>>> @@ -151,15 +156,15 @@ struct meson_nfc {
>>>> struct nand_controller controller;
>>>> struct clk *core_clk;
>>>> struct clk *device_clk;
>>>> - struct clk *phase_tx;
>>>> - struct clk *phase_rx;
>>>
>>> I would have been nice to explain why these clock are no longer
>>> required, in the change description maybe ?
>>
>> i got the reply from our vlsi members that rx and tx doesn't make sense to meson NFC timing. so previous commit about this should be wrong.
>>>
>>>> + struct clk *nand_clk;
>>>> + struct clk_divider nand_divider;
>>>> unsigned long clk_rate;
>>>> u32 bus_timing;
>>>> struct device *dev;
>>>> void __iomem *reg_base;
>>>> - struct regmap *reg_clk;
>>>> + void __iomem *reg_clk;
>>>> struct completion completion;
>>>> struct list_head chips;
>>>> const struct meson_nfc_data *data;
>>>> @@ -406,12 +411,14 @@ static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)
>>>> cmd = NFC_CMD_RB | NFC_CMD_RB_INT
>>>> | nfc->param.chip_select | nfc->timing.tbers_max;
>>>> writel(cmd, nfc->reg_base + NFC_REG_CMD);
>>>> -
>>>> + meson_nfc_drain_cmd(nfc);
>>>
>>> is this clock related ?
>> ok, i will split it in another patch.
>>>
>>>> ret = wait_for_completion_timeout(&nfc->completion,
>>>> msecs_to_jiffies(timeout_ms));
>>>> if (ret == 0)
>>>> ret = -1;
>>>> + /* reset command fifo to avoid lock */
>>>> + writel(NFC_CMD_FIFO_RESET, nfc->reg_base + NFC_REG_CMD);
>>>
>>> Again, not seem to be clock related - does not belong in this patch
>> ok, i will split it in another patch.
>>>
>>>> return ret;
>>>> }
>>>> @@ -988,8 +995,9 @@ static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
>>>> static int meson_nfc_clk_init(struct meson_nfc *nfc)
>>>> {
>>>> int ret;
>>>> + struct clk_init_data init = {0};
>>>> + const char *fix_div2_pll_name[1];
>>>> - /* request core clock */
>>>
>>> Why is the comment bothering you ?
>>>
>>>> nfc->core_clk = devm_clk_get(nfc->dev, "core");
>>>> if (IS_ERR(nfc->core_clk)) {
>>>> dev_err(nfc->dev, "failed to get core clock\n");
>>>> @@ -1002,21 +1010,25 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
>>>> return PTR_ERR(nfc->device_clk);
>>>> }
>>>> - nfc->phase_tx = devm_clk_get(nfc->dev, "tx");
>>>> - if (IS_ERR(nfc->phase_tx)) {
>>>> - dev_err(nfc->dev, "failed to get TX clk\n");
>>>> - return PTR_ERR(nfc->phase_tx);
>>>> - }
>>>> -
>>>> - nfc->phase_rx = devm_clk_get(nfc->dev, "rx");
>>>> - if (IS_ERR(nfc->phase_rx)) {
>>>> - dev_err(nfc->dev, "failed to get RX clk\n");
>>>> - return PTR_ERR(nfc->phase_rx);
>>>> - }
>>>> + init.name = devm_kstrdup(nfc->dev, "nfc#div", GFP_KERNEL);
>>>> + init.ops = &clk_divider_ops;
>>>> + fix_div2_pll_name[0] = __clk_get_name(nfc->device_clk);
>>>
>>> You should be using "fw_name" so CCF looks a DT directly, instead of this
>> ok
>>>
>>>> + init.parent_names = fix_div2_pll_name;
>>>> + init.num_parents = 1;
>>>> + nfc->nand_divider.reg = nfc->reg_clk;
>>>> + nfc->nand_divider.shift = CLK_DIV_SHIFT;
>>>> + nfc->nand_divider.width = CLK_DIV_WIDTH;
>>>> + nfc->nand_divider.hw.init = &init;
>>>> + nfc->nand_divider.flags = CLK_DIVIDER_ONE_BASED |
>>>> + CLK_DIVIDER_ROUND_CLOSEST |
>>>> + CLK_DIVIDER_ALLOW_ZERO;
>>>> +
>>>> + nfc->nand_clk = devm_clk_register(nfc->dev, &nfc->nand_divider.hw);
>>>> + if (IS_ERR(nfc->nand_clk))
>>>> + return PTR_ERR(nfc->nand_clk);
>>>> /* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
>>>> - regmap_update_bits(nfc->reg_clk,
>>>> - 0, CLK_SELECT_NAND, CLK_SELECT_NAND);
>>>> + writel(CLK_SELECT_NAND | readl(nfc->reg_clk), nfc->reg_clk);
>>>> ret = clk_prepare_enable(nfc->core_clk);
>>>> if (ret) {
>>>> @@ -1030,29 +1042,21 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
>>>> goto err_device_clk;
>>>> }
>>>> - ret = clk_prepare_enable(nfc->phase_tx);
>>>> + ret = clk_prepare_enable(nfc->nand_clk);
>>>> if (ret) {
>>>> - dev_err(nfc->dev, "failed to enable TX clock\n");
>>>> - goto err_phase_tx;
>>>> - }
>>>> -
>>>> - ret = clk_prepare_enable(nfc->phase_rx);
>>>> - if (ret) {
>>>> - dev_err(nfc->dev, "failed to enable RX clock\n");
>>>> - goto err_phase_rx;
>>>> + dev_err(nfc->dev, "pre enable NFC divider fail\n");
>>>> + goto err_nand_clk;
>>>> }
>>>> ret = clk_set_rate(nfc->device_clk, 24000000);
>>>> if (ret)
>>>> - goto err_disable_rx;
>>>> + goto err_disable_clk;
>>>> return 0;
>>>> -err_disable_rx:
>>>> - clk_disable_unprepare(nfc->phase_rx);
>>>> -err_phase_rx:
>>>> - clk_disable_unprepare(nfc->phase_tx);
>>>> -err_phase_tx:
>>>> +err_disable_clk:
>>>> + clk_disable_unprepare(nfc->nand_clk);
>>>> +err_nand_clk:
>>>> clk_disable_unprepare(nfc->device_clk);
>>>> err_device_clk:
>>>> clk_disable_unprepare(nfc->core_clk);
>>>> @@ -1061,8 +1065,7 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
>>>> static void meson_nfc_disable_clk(struct meson_nfc *nfc)
>>>> {
>>>> - clk_disable_unprepare(nfc->phase_rx);
>>>> - clk_disable_unprepare(nfc->phase_tx);
>>>> + clk_disable_unprepare(nfc->nand_clk);
>>>> clk_disable_unprepare(nfc->device_clk);
>>>> clk_disable_unprepare(nfc->core_clk);
>>>> }
>>>> @@ -1375,6 +1378,7 @@ static int meson_nfc_probe(struct platform_device *pdev)
>>>> struct device *dev = &pdev->dev;
>>>> struct meson_nfc *nfc;
>>>> struct resource *res;
>>>> + u32 ext_clk_reg;
>>>> int ret, irq;
>>>> nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
>>>> @@ -1396,9 +1400,15 @@ static int meson_nfc_probe(struct platform_device *pdev)
>>>> if (IS_ERR(nfc->reg_base))
>>>> return PTR_ERR(nfc->reg_base);
>>>> - nfc->reg_clk =
>>>> - syscon_regmap_lookup_by_phandle(dev->of_node,
>>>> - "amlogic,mmc-syscon");
>>>> + ret = of_property_read_u32(pdev->dev.of_node,
>>>> + "sd_emmc_c_clkc",
>>>> + &ext_clk_reg);
>>>> + if (ret) {
>>>> + dev_err(dev, "failed to get NAND external clock register\n");
>>>> + return ret;
>>>> + }
>>>> +
>>>> + nfc->reg_clk = devm_ioremap(&pdev->dev, ext_clk_reg, sizeof(int));
>>>
>>> That's how you should get a register region.
>>> If you want an example of a device claiming several region on amlogic,
>>> have a look at the pinctrl driver.
>> ok
>>>
>>>> if (IS_ERR(nfc->reg_clk)) {
>>>> dev_err(dev, "Failed to lookup clock base\n");
>>>> return PTR_ERR(nfc->reg_clk);
>>>
>>> .
>
> .
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